The value of [Key] fields isn't directly assigned (note that there is even private setter) - we consider entity never exists without a key, so key is assigned during entity initialization. I.e. you simply can't see an entity w/o assigned key - @ any event you can handle, or protected method that can be overriden.

Actually, we fetch all the field values from internal row-like structure: Tuple. So during initialization, [Key] field values are assigned directly to Tuple fields. That's why event for [Key] is never raised.

I'm not fully sure if this must be fixed - we consider it's a natural behavior:

• Entity appears with key

• Key can never change. The only exception from this rule is key remapping that happens on completion of DisconnectedState.ApplyChanges method - here we don't set key fields directly as well, but sent "all properties are changed" via INotifyPropertyChanged interface on completion of this process).

**> First time when the property changes

Second time is during ApplyChanges()**

That's normal, since we replay the operations on "connected" entities.

You can distinguish between these two cases using Session.IsDisconnected or Session.DisconnectedState properties.